Here's a video of the problem:

Just to explain what's going on- to begin with I have to motors going full speed forward, then after looking at both wheels I put it into full reverse then back into full speed forward, during the jittering I am holding the stick on the transmitter in one position never changing speed or direction, the wheels just stop.
At the end I quickly how the insides trying to show the flashing/sparking inside the motors caused by the starting and stopping.